Recovery catheter assembly

ABSTRACT

An example of recovery catheter assembly comprises an actuator element and a mechanically radially expandable and contractible recovery device operably connected to the actuator element. The recovery device has proximal and distal blocking portions and a central portion therebetween. The recovery device is at least partially placeable in a first, radially collapsed configuration and in a second, radially expanded configuration by manipulation of the actuator element. When in the second, radially expanded configuration, the proximal and distal blocking portions have radial dimensions greater than the radial dimension of the central portion thereby at least partially defining a collection chamber at the central portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 13/041,102, filed Mar. 4, 2011, which claims priority benefit under35 U.S.C. §119(e) to U.S. provisional application No. 61/339,548, filedMar. 6, 2010; U.S. provisional application No. 61/341,587, filed Apr. 1,2010; and U.S. provisional application No. 61/459,164, filed Dec. 8,2010. The disclosure of the aforementioned patent applications U.S.application Ser. No. 13/041,102, U.S. provisional application No.61/339,548, U.S. provisional application No. 61/341,587, and U.S.provisional application No. 61/459,164 are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to systems and methods of local organperfusion of tumors or other serious conditions with one or more highdose treatment substances, isolating the venous outflow, collecting it,filtering it, and returning it to the body after removing the high dosetreatment substance(s).

2. Description of Background Art

There are several methods of treating cancerous tumors includingsurgery, chemotherapy, focal ablation by delivery of various forms ofenergy, radiation, amongst others. Often, tumors are not resectable bysurgery because they have spread into the surrounding tissues or todistant tissues such as the liver, lung, or brain. The treatment ofmetastatic disease to these organs is done with chemotherapy, focalsurgical resection and focal ablation when there are only a few lesions,and occasionally with radiation. Oftentimes, the metastatic disease isdiffuse and not amenable to surgery, radiation or focal ablation. Thisleaves chemotherapy as the only alternative, and the effectiveness ofthe chemotherapy is limited by the systemic toxicities cause by the drugincluding bone marrow suppression, neutropenia, nausea, diarrhea,anorexia, wasting, cachexia, bacterial or viral overgrowth amongstothers.

A system, process, and method of isolated perfusion of organs with avery high dose of a chemotherapeutic agent, collection of the effluentvenous blood from that organ before it enters the systemic circulation,filtering the chemotherapeutic agent from the collected blood, andreturning the filtered blood without the chemotherapeutic agent to thesystemic circulation has been described by Glickman in U.S. Pat. Nos.5,817,046, 5,893,841, 5,897,533, 5,919,163, and 7,022,097 and by Boddenin U.S. Pat. No. 5,069,662. This system is currently marketed byDelcath, Inc., of New York, N.Y., as the Percutaneous Hepatic Perfusion(PHP) apparatus for the purpose of treating metastatic disease andprimary tumors of the liver. In essence, a very high dose of achemotherapeutic agent is infused into the hepatic artery over a periodof time, usually from 30 minutes to an hour. The high dosechemotherapeutic agent perfuses the liver and is much more effectivethan a traditional systemic dose administered intravenously. This drugis taken up by the tumor and the remainder flows into the hepatic veins,which are a series of veins that drain from the liver into the upperinferior vena cava (IVC.) This blood which still contains toxic levelsof the chemotherapeutic agent is collected by an isolation device whichis part of this special apparatus (PHP). The hepatic venous bloodisolation device is a double balloon system that is deployed in theinferior vena cava, the balloons being inflated above and below thehepatic veins, the hepatic venous effluent collected into a catheter andpumped through a filter outside the body that removes thechemotherapeutic agent, and returned to the superior vena cava viaanother catheter. A through return lumen, also referred to as a returnchannel, is provided to allow blood in the inferior vena cava from thelower body and kidneys to flow back to the heart while the balloons areoccluding the vena cava.

While the current prior art apparatus is effective in treating the tumoror tumors of the liver, it is somewhat cumbersome to use, as the doubleballoons may occlude the renal and/or adrenal veins, and the balloonstend to occupy more space in the inferior vena cava than is desirable.Moreover, the through lumen that transmits blood from the lower inferiorvena cava to the heart is not large enough to accommodate the volume ofblood returning to the heart. This frequently results in a sudden dropin the patient's blood pressure, and occasionally a shock likecondition. Since it is expected that the patient will need at least somelevel of resuscitation, an anesthesiologist is in attendance to dealwith these problems. Obviously, the risk to the patient and the cost ofthe procedure increases dramatically because these problems with theprior art technology. This is significant, not only from the risk to thepatient, but also because it may prevent interventionalists frompursuing this strategy of treatment for their patients and theirreferring physicians. There is the risk that these problems with theprior art device and technology may prevent this very effective systemof therapy from being fully adopted by the medical community, therebydepriving thousands of patients who would have benefited from thetherapy otherwise. There are significant problems that can result fromthese iatrogenically created complications such as renal and adrenalvein thrombosis, unstable perfusion of the heart, brain, and kidneys,resulting in heart attack, stroke, kidney damage amongst othercomplications, in a patient who is already compromised because of theunderlying malignancy. These complications are the result of the use ofthe primitive balloon technology and method of occluding, altering, orre-directing blood flow in the human body.

The balloons of the prior art device limit the size of the through lumenas the expanded balloons must occupy most of the inferior vena cava toeffectively isolate the hepatic veins. This limits the amount of bloodthat can be returned from the inferior vena cava to the right atrium,resulting in the problems noted in the above paragraph. The footprint ofthe expanded balloons, especially the caudal balloon, in the inferiorvena cava is problematic as the distance between the more caudal hepaticveins and the renal/adrenal veins is frequently less than the footprintof the expanded balloon.

In reviewing a series of over 50 CT scans of the abdomen, the inventorhas determined from measurements of the cavoatrial junction to theorifice of the left renal vein that the current prior art device ofGlickman is likely to partially occlude the left renal vein in greaterthan ⅓ of the cases. If a 15 mm compensating factor is utilized forcurvature and other measurement inaccuracies, then there would likelystill be greater than 20% of cases in which the left renal vein would beat least partially covered by the caudal balloon of the current device.

Also, different diameter devices may be needed as measurement of theanteroposterior (AP) and transverse dimensions of the IVC revealed agreat variation in those measurements. Average AP and transversedimensions in the upper IVC, mid retrohepatic IVC and immediate suprarenal vein IVC were 23.6 mm and 30.4 mm, 20.0 mm and 22.7 mm, and 20.2mm and 28.3 mm, respectively. A minimal AP dimension of only 8 mm waspresent in one subject while a maximum AP dimension of 36 mm occurred inanother subject. Transverse dimensions varied from 10.2 mm to 40 mm indifferent subjects. The measurements taken may not apply to populationsof different ethnicity and may vary even more in those differentpopulations and age groups. Moreover, within the same patient, the IVCmeasurements many times revealed a large oblong supradiaphragmatic IVC,a smaller more rounded mid retrohepatic IVC, and a tilted, oblongconfiguration of the IVC just above the renal veins. In fact, the tiltedoblong configuration just above the renal veins was frequently tilted inthe opposite direction from the tilted oblong configuration of thesupradiaphragmatic IVC.

SUMMARY OF THE INVENTION

Examples of the present invention will successfully and effectivelycollect the hepatic venous effluent, isolating it from the systemiccirculation without the problems caused by the current double balloonsystem. According to some examples, isolation will occur withoutblockage of adrenal or renal veins while providing a large channel forblood to flow unimpeded from the inferior vena cava to the heart withoutthe use of balloons.

A first example of recovery catheter assembly comprises an actuatorelement and a mechanically radially expandable and contractible recoverydevice operably connected to the actuator element. The recovery devicehas proximal and distal ends and comprises proximal and distal blockingportions at the proximal and distal ends thereof. The recovery devicealso has a central portion between the proximal and distal blockingportions. The recovery device is at least partially placeable in afirst, radially collapsed configuration and in a second, radiallyexpanded configuration by manipulation of the actuator element. When inthe second, radially expanded configuration, the proximal and distalblocking portions have radial dimensions greater than the radialdimension of the central portion thereby at least partially defining acollection chamber at the central portion. In some examples the recoverydevice is fully placeable in the first, radially collapsed configurationand in the second, radially expanded configuration by manipulation ofthe actuator element. In some examples the recovery device comprisesproximal and distal toroidal blocking balloons at the proximal anddistal ends of the recovery device. Some examples include a hollowrecovery catheter having a sidewall and defining a recovery lumen. Someexamples may further comprise a lateral passageway extending through thecentral portion of the recovery device and the sidewall of the recoverycatheter, the parts of the proximal and distal blocking portions and thecentral portion at least partially defining the collection chamber beingliquid impervious with the exception of the passageway, whereby liquidin the collection chamber can pass through the passageway and into andthrough the recovery lumen. In some examples the recovery cathetercomprises proximal, intermediate and distal portions, the lateralpassageway is located along the intermediate portion of the recoverycatheter, a blood pump is located along the distal portion of therecovery catheter, and a filter element is located along the distalportion of the recovery catheter for filtering out at least one agentfrom fluid flow through the recovery catheter lumen. In some examples afirst pressure sensor is at the collection chamber, a second pressuresensor is positioned distal of the recovery device, a filter element anda pump are operably coupled to the recovery catheter to pump fluidthrough the recovery catheter and filter fluid passing through therecovery catheter, and the pump is operably coupled to the first andsecond pressure sensors to permit control of the pressure within thecollection chamber during use. In some examples a filter element and apump are operably coupled to the recovery catheter to pump fluid throughthe recovery catheter and filter fluid passing through the recoverycatheter, a pressure sensor is located proximal to the pump, and thepump is operably coupled to the pressure sensor to permit control of thepressure within the collection chamber during use. In some examples theactuator element comprises first and second actuator elements, therecovery device comprises a proximal end operably connected to the firstactuator element and a distal end operably connected to the secondactuator element; the recovery device is at least partially placeable inthe first, radially collapsed configuration and in the second, radiallyexpanded configuration by manipulation of the first and second actuatorelements.

A second example of a recovery catheter assembly, for use within a bodypassageway at an ostium, includes an outer, actuator sheath having adistal portion and an inner, hollow recovery catheter having a sidewall.The recovery catheter defines a recovery lumen and has a distal end. Therecovery catheter is housed within the actuator sheath. An actuator wireextends along the recovery catheter and has a tip positioned distal ofthe distal end of the recovery catheter. A mechanically radiallyexpandable and contractible recovery device has a proximal end securedto the distal portion of the actuator sheath by a proximal extensionelement and a distal end secured to the tip of the actuator wire by adistal extension element. The recovery device comprises proximal anddistal blocking portions at the proximal and distal ends thereof, acentral portion between the proximal and distal blocking portions, and areturn lumen extending between the proximal and distal ends thereof. Therecovery device is placeable in a first, radially collapsedconfiguration when the actuator wire is pushed distally to a distalactuator wire position relative to the recovery device and the actuatorsheath is pulled proximally to a proximal actuator sheath positionrelative to the recovery device. The recovery device is placeable in asecond, radially expanded configuration when the actuator wire is pulledproximally to a proximal actuator wire position relative to the recoverydevice and the actuator sheath is pushed distally to a distal actuatorsheath position relative to the recovery device. When in the second,radially expanded configuration, the proximal and distal blockingportions have radial dimensions greater than the radial dimension of thecentral portion thereby defining a collection chamber at the centralportion, and the proximal and distal expansion elements have openregions to permit fluid flow through the return lumen of the recoverydevice. A lateral passageway extends through the central portion of therecovery device and the sidewall of the recovery catheter. The parts ofthe proximal and distal blocking portions and the central portiondefining the collection chamber are liquid impervious with the exceptionof the passageway, whereby liquid from an ostium of a liquidtransporting vessel opening into the collection chamber can pass throughthe passageway and into and through the recovery lumen.

A third example of a recovery catheter assembly, for use within a bodypassageway at an ostium, comprises an outer, actuator sheath having adistal portion and an inner, hollow recovery catheter having a sidewall.The recovery catheter defines a recovery lumen and a distal end. Therecovery catheter is housed within the actuator sheath. The recoverycatheter has an actuator wire extending along the recovery catheter anda tip positioned distal of the distal end of the recovery catheter. Amechanically radially expandable and contractible recovery device has aproximal end secured to the distal portion of the actuator sheath by aproximal extension element and a distal end secured to the tip of theactuator wire by a distal extension element. The recovery devicecomprises proximal and distal toroidal blocking balloons at the proximaland distal ends thereof, a central portion between the proximal anddistal blocking portions, and a return lumen extending between theproximal and distal ends. The recovery device is placeable in a first,radially collapsed configuration when (1) the blocking balloons are indeflated states, and (2) the actuator wire is pushed distally to adistal actuator wire position relative to the recovery device and theactuator sheath is pulled proximally to a proximal actuator sheathposition relative to the recovery device. The recovery device isplaceable in a second, radially expanded configuration when (1) theblocking balloons are in inflated states, and (2) the actuator wire ispulled proximally to a proximal actuator wire position relative to therecovery device and the actuator sheath is pushed distally to a distalactuator sheath position relative to the recovery device. When in thesecond, radially expanded configuration (1) the proximal and distalblocking balloons have radial dimensions greater than the radialdimension of the central portion thereby defining a collection chamberat the central portion, and (2) the proximal and distal expansionelements have open regions to permit fluid flow through the return lumenof the recovery device. A lateral passageway extends through the centralportion of the recovery device and the sidewall of the recoverycatheter. The parts of the proximal and distal blocking portions and thecentral portion defining the collection chamber are liquid imperviouswith the exception of the passageway. Whereby liquid from an ostium of aliquid transporting vessel opening into the collection chamber can passthrough the passageway and into and through the recovery lumen.

An example of a method for directing a fluid, which passes through anostium into a body passageway, to a fluid recovery device is carried outas follows. A radially expandable and contractible recovery device ispositioned within a body passageway at an ostium with the recoverydevice in a first, radially collapsed configuration, the recovery devicehaving a proximal end and a distal end. The recovery device is placed ina second, radially expanded configuration, the placing step carried outat least in part by the mechanical manipulation of at least onemechanical actuator element thereby mechanically expanding the proximaland distal blocking portions so that when the recovery device is in thesecond, radially expanded configuration. The proximal and distalblocking portions have radial dimensions greater than the radialdimension of the central portion thereby at least partially defining acollection chamber at the central portion. Fluid from the collectionchamber is directed into the recovery device. In some examples theradially expanded configuration placing step is carried out using firstand second mechanical actuator elements operably coupled to proximal anddistal ends of the recovery device. In some examples the radiallyexpanded configuration placing step is carried out completely by themechanical manipulation of the at least one actuator element. In someexamples the radially expanded configuration placing step furthercomprises inflating proximal and distal toroidal blocking balloons atthe proximal and distal ends of the recovery device.

An example of a method for recovering venous effluent from an organ, theorgan having a distal vein and a draining vein, is carried out asfollows. A funnel device of a recovery catheter assembly is placedwithin a tubular body vessel at a venous ostium of an organ beingtreated, the funnel device having an open end. The open end of thefunnel device is placed within the distal vein of the organ at theostium. The funnel device is forced against the venous wall to create aseal between the funnel device and the draining vein thereby creating acollection chamber defined between the funnel device and the organ. Anagent is infused into the patient. Fluid from the organ is collected inthe collection chamber. The collected fluid is filtered. The filteredcollected fluid is returned to the patient.

An example of a method for determining the effectiveness of a seal at acollection chamber created between a recovery device of a recoverycatheter assembly and an organ from which fluid is collected is carriedout as follows. An indicator agent and a therapeutic agent are infusedinto a patient. A fluid, which passes through an ostium of an organ intoa body passageway, is collected in a collection chamber defined betweena fluid recovery device of a recovery catheter assembly and the organ.The collected fluid is processed. The processing step comprises removingthe indicator agent and the therapeutic agent from the collected fluid.The processed fluid is returned to the patient. Systemic fluid iscollected from the patient. The collected systemic fluid is tested forthe presence of the indicator agent.

An example of a method for removing a therapeutic agent from a patientis carried out as follows. A therapeutic is infused agent into apatient. A fluid passing from an organ is collected. A binding materialcomprising an affinity agent is added into the collected fluid. Thetherapeutic agent within the collected fluid is bound to the affinityagent. The collected fluid and the binding material are processed. Theprocessing step comprises removing the binding material with thetherapeutic agent bound thereto from the collected fluid. The processedfluid is returned to the patient.

Other features, aspects and advantages of the present invention can beseen on review the figures, the detailed description, and the claimswhich follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a patient being treated with a prior art isolationapparatus.

FIG. 2 shows a prior art isolation apparatus with the balloons indeflated states.

FIG. 3 shows the prior art apparatus of FIG. 2 with the balloons ininflated states.

FIGS. 4-8 are illustrated examples of recovery catheter assemblyincluding mechanically assisted expansion mechanisms made according tothe present invention

FIG. 4 shows a first example of a mechanically assisted expansionapparatus made according to the invention.

FIG. 4A shows the structure of FIG. 4 in a collapsed state.

FIG. 4B is a cross-sectional perspective view of the structure of FIG.4.

FIGS. 5A, 5B and 5C are cross-sectional views taken along lines 5A-5A,5B-5B and 5C-5C in FIG. 4, respectively.

FIG. 6 illustrates an alternative to the example of FIG. 4 includingtoroidal balloons used in conjunction with the mechanically assistedexpansion mechanism.

FIG. 7 illustrates a further alternative similar to that of FIG. 6 usingobliqued toroidal balloons.

FIG. 8 shows an alternative example similar to that of FIG. 6 in whichthe pump and filter are placed in extended section of recovery catheter.

FIGS. 9-16 show other examples of recovery catheter assemblies.

FIG. 9 shows a recovery device including a funnel catheter.

FIGS. 10A and 10B show the funnel catheter of FIG. 9 in more detail.

FIGS. 11A, 11B and 11C show a retrievable temporary balloon expandablestrut in three different states.

FIG. 12 is a cross-sectional view taken along line 7-7 of FIG. 11C.

FIG. 13A shows a funnel catheter.

FIG. 13B shows a retrievable isolation apparatus including an expandablemesh grade structure.

FIG. 13C shows the structure of FIG. 13B in use.

FIGS. 14, 15 and 16 show additional examples of retrievable isolationapparatus.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The following description will typically be with reference to specificstructural embodiments and methods. It is to be understood that there isno intention to limit the invention to the specifically disclosedembodiments and methods but that the invention may be practiced usingother features, elements, methods and embodiments. Preferred embodimentsare described to illustrate the present invention, not to limit itsscope, which is defined by the claims. Those of ordinary skill in theart will recognize a variety of equivalent variations on the descriptionthat follows Like elements in various embodiments are commonly referredto with like reference numerals.

FIG. 1 is a representation of a patient 2 being treated with a prior artapparatus. The drug or substance is injected by a syringe 4 or pump (notshown) into the hepatic artery 5 and perfuses the liver 3. The hepaticvenous effluent is collected by the double balloon catheter 9 in theupper inferior vena cava 7 and directed into the connecting tubing 17 tothe pump 21, then to the filter 43 via the connecting tubing 41 betweenpump 21 and filter 43, and then the filtered blood is transported backinto the patient's 2 systemic circulation by connecting tubing 44returning blood to the internal jugular vein.

FIG. 2 is a prior art isolation apparatus 139 demonstrating theuninflated balloons 143, 144 and the holes 141 in the external catheter140 through which the hepatic venous effluent flows into an externalsituated lumen. The return channel or through lumen (not shown) thattransmits the inferior vena caval blood to the right atrium is in acentral lumen (not shown) which is necessarily smaller than needed asthe catheter 142 must contain the recovery lumen for the hepatic venouseffluent, inflation channels for the balloons, and the through returnlumen for IVC blood to pass to the right atrium.

FIG. 3 is the prior art apparatus 139 with the balloons 143 and 144expanded so that the section of inferior vena cava (not shown) betweenthe balloons 143 and 144 is isolated. The caudal balloon 143 is placedbelow the most caudal hepatic veins (not shown) and the cephalic balloon144 is placed near the juncture of the inferior vena cava (not shown)and the right atrium (not shown). Blood flowing out of the hepatic veinsinto this section of isolated inferior vena cava is collected throughthe openings 141 in the wall of the catheter into an external lumen andtransported via tubing 17, 41, 44 to the pump 21 and filter 43 and thenback into the body 2 as in FIG. 1. There is central channel (not shown)that serves as the return through channel to transport the blood fromthe IVC to the right atrium. Because of the external collection channelof the isolation apparatus, two balloon inflation channels and the wallsof these channels, the central return through channel has an inadequateannular space to transport sufficient blood from the IVC to the rightatrium. This constriction is necessary because of the design of theprior art device, and, as mentioned above, is problematic. Moreover, onecan easily see that the footprint of the expanded balloons 143, 144 isso large that other vital veins may easily be inadvertently occluded.The current invention will obviate these problems in one of severalconfigurations described henceforth.

Ideally, the device of the present invention should be relatively smallfor easy insertion, and then expand in the inferior vena cava tofunction, then contract to a small size again for removal. In fact,while the above descriptions of the different embodiments have discussedthe use of materials that are expansile, expansible, self expanding,balloon expansible, self contracting, and so forth, it is the inventor'sconclusion that after the review of the CT scans on 50 patients that thewide variety of size and shapes of the inferior vena cava, the criticallength needed to cover the hepatic venous ostia but not occlude theadrenal and renal veins, the need for a small footprint caudally, andthe need for an adequate through return lumen places unusual demands ona device which cannot be met by simply applying prior art techniques(self expanding, balloon expandable, etc.) that may have been usedelsewhere in the vascular system to a hepatic venous effluent recoverycatheter. Hence, one preferred embodiment as discussed below withreference to FIGS. 4 and 5A-5C, as well as the other embodiments, willfunction best with a system of mechanically assisted expansion, whichutilizes a mechanism proximally (for example outer actuator sheath 73)and a mechanism distally (for example actuator rod 154) that willprovide additional tension on the proximal and distal flares 131, 132 toenhance and assist the expansion and contraction of them. While severalof the embodiments utilize balloon expansion and one embodiment utilizesa self expanding braid, a presently preferred configuration is one thatuses a non balloon, mechanically assisted expansion, such as recoverydevice 138 of FIGS. 4 and 5A-5C.

The reasons that mechanically assisted expansion will work better than aself expanding design in the inferior vena cava include the following.

1. Foreshortening: With self expansion there will be a significantamount of foreshortening upon expansion of the device, and the amount offoreshortening will depend on the size and shape of the IVC. If thediameter of the IVC is small, there will be less foreshortening than ifit is large. There is a need to cover all of the hepatic veins (whichtypically range from 6.5-7 cm top to bottom), but not to occlude adrenalor renal veins. Therefore the length of the device when deployed iscritical. One generally does not have control over the length with aself expanding device and this may result in the occlusion of the renaland adrenal veins. Alternatively, one could control the length with amechanically assisted expansion, as one could adjust the tension on theflares (flares 131, 132 discussed below with reference to FIG. 4) tomatch the anatomy present in the individual patient. Hence, in a patientwith a small IVC, one would increase the tension on the flares creatingless length than would be present without this added mechanicalassistance, adding an element of control not present with a purely selfexpanding system. This reason alone provides a strong incentive for notusing self expanding only designs and using a mechanical assistedexpansion design.

2. To be effective at all, a self expanding braid must be oversized andthe elastomeric membrane applied in the oversized state, less themembrane will cause the braid to contract. When one attempts to removethe self expanding device (typically approximately 45 mm fully distendedin oversized state) through a 15 Fr. (5 mm) catheter, one will have todeal with the extra membrane material which will become irregularlyfolded and clumped when the braid is contracted. This is especially truewhen removing the distal annular flare as the center portion of thebraid is attached to the recovery tubing and not allowed to contractfully by proximal tension on the braid. In other words, one may be ableto remove the proximal annular flare and the center portion by tractionon the braid, but one should expect difficulty in removing the distalannular flare which has been oversized purposefully with excess membranematerial in a self expanding configuration. Mechanically assistedexpansion and contraction would obviate this problem.

3. A self expanding tubular mesh braid typically exerts less radialforce than a laser cut stent (which would be extremely expensive),therefore one may need a mechanical assisted expansion to create a tightseal, i.e., extra radial tension force not present with self expansion,especially considering the many different shapes and angles in theinferior vena cava. In fact, the acute angle present in the immediatesuprarenal inferior vena cava that was frequently demonstrated on the CTstudy mentioned above would cause particular problems for a selfexpanding device as there would be inadequate seating of the braidbecause of the acute angle at this location, and hence inadequatesealing of the device. One would need active expansion, i.e., mechanicalassistance, to drive the braid with more force than would be possiblewith a purely self expanding system.

4. Tradeoff in wire sizes and number of wires: The device can be mademore compact with fewer and smaller wires, but will have less radialforce and lesser chance of creating a tight seal if only self expansionis utilized. A compact device can be constructed if there is mechanicalassisted expansion to provide for a secure seal.

5. As detailed later, the presence of the recovery catheter attachedonly to the ventral aspect of the braid in FIG. 4 will tend to cause therecovery catheter to be centered in the vessel when it is actuallyeccentrically placed. The use of a self expanding mechanism may causeunequal pressures against the IVC wall by the flares, especially giventhe varying shapes of the IVC, and hence the potential for a less thansecure seal. The use of a mechanical assist mechanism would provide foradditional annular tension that would overcome this potential problem.

6. Another property of tubular braided structures is that there is acritical braid angle that needs to be achieved to provide radialstrength. When this critical angle is achieved the braided tube becomesstronger and the inward force required to collapse the braiddramatically increases. This critical angle of the braid is more readilyachievable with an active expansion, or mechanically assisted expansion,that would tend to drive the braid to a larger diameter than would bepossible with a purely self expanding system. In fact, the criticalangle that does give the braided structure its optimal braid angle andhence optimal radial strength may not be achievable at all with a purelyself expanding device. Moreover, even if this critical braid angle wereachieved with a purely self expanding system, collapsing the braid forretrieval may be even more problematic.

7. A self expanding system needs an outer sheath to constrain the devicefor insertion and retrieval. With an active system to control theexpansion and contraction of the device, this outer sheath may not beneeded creating an overall smaller size profile than would be achievablewith a purely self expanding system.

The reasons a mechanically assisted expansion mechanism as describedsubsequently in FIGS. 4-8 will work better than a balloon-only expandedmechanism as demonstrated in some of the current embodiments in priorart devices are:

1. Obviating the use of the balloon makes the device simpler.

2. The balloon-only assisted expansion may not provide the force neededto create a tight seal or control the length when the balloon isdeflated to allow IVC blood to return to the heart.

3. In some situations balloon expansion mechanism may be used inconjunction with a mechanical assisted expansion, and some of thecurrent embodiments reflect this.

Hence, for the reasons listed above, the novel mechanically assistedexpansion of the current invention is superior to previously describedstand alone techniques and methods such as balloon-alone expansion andself expansion. As used in this application, mechanically assistedexpansion is carried out with mechanical expansion structure with orwithout the use of a balloon to assist expansion in the preferredembodiments.

One preferred embodiment of a recovery catheter assembly 136 is shown inFIGS. 4-4B and 5A-5C, and includes a recovery device 138 using anexpandable or expansible and collapsible mesh braid 130 with anelastomeric covering 97. Although it may be self expanding, selfcontracting, it is preferably expansible by mechanical expansionstructure which will be described subsequently.

The recovery device 138 in this configuration has a “dog bone”configuration with the protruding flares 131, 132 on each end creatingthe blocking element that define the extent of the hepatic venouseffluent collection chamber 94 (HVECC) covering the ostia 51 of hepaticveins 52. Braiding techniques, heat treating of the nitinol (or othermaterial from which the braid 130 is made), the attachment of the braid130 to the recovery catheter 76, defining a recovery lumen, and possiblelay-ins in the braid will determine the shape of the device 138. Themesh braid 130 of the device 138 is covered with or coated with anelastomeric substance 97 in all but its proximal and distal endscreating a modified cylindrical channel within the tubular mesh braid130. The elastomeric covering, typically of a silicone composition orsome other biocompatible material that is resistant to degradation bythe chemotherapy, or other, agent, may extend proximal to the proximalflare 131 and distal to the distal flare 132, but would not cover theends of the device 138. This will allow a very generous through returnchannel 124 for blood to flow from the lower IVC lumen 99 into the rightatrium (not shown.)

The expanding structure 100 may be made of a mesh braid, laser cutmaterials, or any other generally tubular, radially expandablemechanical structures that can be expanded into a more or less tubularconfiguration that would allow an adequate through channel for IVC bloodto return to the right atrium without much impendence or obstruction.The present invention is also directed to methods of using generallytubular, radially expandable mechanical structure to convey IVC bloodfrom an area near the renal veins to the supradiaphragmatic IVC or theright atrium while collecting hepatic venous effluent, and all deviceswhich would facilitate such a method with or without the extracorporealfiltration system described above and elsewhere.

In the preferred embodiments of FIGS. 4-8, the expanding structure 100is expanded by means of a proximal actuator sheath 73 and a distalactuator wire 154 attached to a proximal wire set 146 and to a distalwire set 147 of the mesh braid 130, respectively. By exerting forwardpressure upon the outer actuator sheath 73 with respect to the recoverylumen 76, the proximal flare 131 will expand to the wall of the inferiorvena cava creating a seal and providing expansion of the proximalportion 124 of the through return channel 124 defined between actuatorshaft 73 and the elastomeric coated mesh braid 130. By exerting apulling pressure on the actuator wire 154, the distal flare 132 willexpand to the wall of the inferior vena cava creating the distal sealand providing the expansion of the distal portion of the through returnchannel 124. The hepatic venous effluent collection chamber 94 iscreated between these two flared ends of the device. In addition tocreating collection chamber 94, the mechanically expanding structure 100also creates the return channel 124, discussed in more detail below.

The recovery catheter 76 that collects blood and the chemotherapeuticagent from the HVECC 94 and transfers it to the extracorporeal pump (notshown) is bonded to the ventral surface of the coated expandable meshbraid 130. At least one hole 95, and preferably several holes 95, areplaced through the braid 130 and material 97 covering the braid and intothe lumen 68 of the recovery catheter 76. See FIGS. 5A-5C. This allowscommunication of the lumen 68 of the recovery catheter 76 with the HVECC94 and the hepatic venous effluent would flow from the HVECC 94 throughthe holes 95 and into the recovery catheter 76, and then be transportedextracorporeally to be filtered before being returned to the body.

The bonding of the catheter to the braided structure is of specialconcern as this may be a potential point of failure. A simplecircumferential bonding (not shown) around the hole through the wall ofthe braided device 130 and the holes 95 in the recovery catheter 76 maysuffice, but it is anticipated that a broad area bonding (not shown) ofthe surface of the catheter to the braided structure, as well as a focalcircumferential bonding, may be needed and would provide an extra degreeof safety. Other members (not shown), such as wires, may be utilized toencircle the recovery catheter 76 and engage the coated mesh braidstructure 130 to fix the recovery catheter to the mesh braid structure,in addition to the bonding described above. Prevention of leakage of thetoxic hepatic venous effluent into the systemic circulation is a highpriority.

Since the coated braided structure 130 is bonded to the recoverycatheter 76 in the more or less mid portion of the braided structure130, collapsing of the braid will be more difficult than if it were notbonded, in that the proximal mechanism will not collapse the distalaspect of the braided structure. Therefore, in this particularembodiment, a second collapsing mechanism is supplied in the form of astiff push/pull rod or actuator wire 154 that occupies a channel 69, seeFIGS. 5A-5C, within the wall of the recovery catheter 76. The distalwire set 147 of the braided structure 130 is attached to this rod orwire 154 by crimping, soldering, or by other appropriate means.Retracting the wire 154 will cause the braided structure 130 to expandagainst the vessel wall 155 and form a seal 156 about the HVECC 94 thatwill be created. Advancing the wire/rod 154 will cause the braidedstructure 130 to collapse for insertion and removal. The proximalportion 131 of the braided structure 130 will be expanded and collapsedby the movement of the actuator sheath 73 with respect to the recoverycatheter 76.

Of special note is the eccentric nature of the recovery catheter 76 inFIGS. 4 and 4A. The braid 130 attached proximally to actuator sheath 73through proximal wire set 146 will tend to center the recovery catheter76 in the lumen 99 of the blood vessel IVC. Ideally, the recoverycatheter 76 needs to remain eccentrically placed with in the lumen 99 ofthe vessel to maintain as large as possible return channel 124 for theblood to flow unimpeded. The braid may not provide equal pressureagainst the vessel wall 155 at the flared ends 131, 132 because of theeccentricity and this may contribute to unequal sealing of the HVECC 94.These negative features may be partially overcome by different braidingtechniques, heat set techniques, and additional lay-ins for braid 130amongst other techniques. Additionally, the members of the braid 130,that is the proximal wire set 146, attached to actuator sheath 73 wouldbe shorter on the ventral aspect of the device which may help resolvethis difficulty somewhat, and the distal wire set 147 of braid 130 isattached to the distal tensioner wire 154 which is indeed centeredwithin the blood vessel lumen 99. In other words, the attachment of theproximal braid 146 to the actuator sheath 73 in such a manner thatforward pressure on the actuator sheath will provide annular radialforce to the proximal flare 131 may be essential to providing a tightseal against the wall of the IVC. Without this added pressure, theeccentric nature of the flare 131 may prevent equal or adequate pressureagainst the IVC wall 155, especially since the size and shape of the IVCis so varied from patient to patient and even within the same patient.

Even another alternative embodiment as shown in FIG. 6 utilizes amechanically assisted expansion device as shown in FIG. 4, but themechanically assistance is utilized only to expand the return channel124. The HVECC 94 is defined by balloons 180, 181, which may be toroidalballoons, on the proximal and distal ends of the through return channel124. The presence of the mechanically assisted expansion apparatus willovercome many of the problems inherent in a self expanding device thatare listed herein and allow easier placement and repositioning, easierdeployment and, more importantly, easier recovery of the tubularrecovery device 138. The mechanically assisted expansion will also allowmore pressure to be exerted radially and prevent collapse of the returnchannel 124 when the balloons 180, 181 are inflated. The balloons, beingmore flexible than the braided flares 131, 132 of other embodiments,will conform to the acute angles within the inferior vena cava betterthan the braided wire structures and provide for a more consistent andpredictable seal. There has been no problem with leakage of the priorart device that is currently in use which utilizes balloons. Theballoons function well to contain the hepatic venous effluent. Theproblem with the prior art device is that the balloons are too large andocclude the renal and adrenal veins in some cases, and that the throughreturn channel is too small to convey a sufficient volume of blood fromthe kidneys and lower body via the inferior vena cava to the heart. Thislatter problem causes the patient to go into shock, as well as a myriadof other problems, enumerated previously. Hence, the balloons are notthe problem with the currently used prior art device, it is the size ofthe balloons and the size of the through return lumen that isproblematic. These deficiencies are addressed with various embodiments,including those of FIGS. 6 and 7.

The braided tubular structure is covered with an impermeable and elasticsubstance 97 that is resistant to chemotherapeutic compounds as theprior embodiments. It is essentially tubular rather than having theflares 131, 132 or expanded ends as present in FIG. 4. The tubularstructure representing the return lumen 124 is attached to an inner,recovery catheter 76 which communicates with the hepatic venous effluentcollection chamber (HVECC) 94 via one or more apertures 95. An outeractuator sheath 73 is slideable relative to the inner recovery catheter76 to assist with expansion and collapse of the tubular return channel124. The braid 130 is attached to this recovery catheter 76 so thattension can be provided to expand the braid, or to assist with theexpansion of the braid, by advancing the outer actuator sheath 73 withrespect to the inner, recovery catheter 76, and tension can be providedto collapse the braid, or assist with collapsing the braid morecompletely, by withdrawing the outer sheath 73 with respect to the innercatheter 76.

A stiff push wire or actuator wire 154 may be attached to the distalwire set 147 to expand or collapse, or assist the expansion or collapseof the tubular braided structure as previously illustrated in FIG. 4.Expansion or assistance with expansion is accomplished by withdrawingthe wire 154 with respect to the inner, recovery catheter 76. Collapseor assistance with collapse of the tubular braided through returnchannel 124 is accomplished by advancing the wire 154 with respect tothe inner catheter 76. The wire 154 preferably is housed within a lumen69 of the wall of the inner catheter 76 as per FIGS. 5A, 5B, and 5C.

The proximal balloon and the distal balloons are attached to the outersurface of the tubular braided through return lumen and are inflated viainflation lumens 66, 67 as pictured in FIGS. 5A, 5B, and 5C, althoughthe inflation lumens may be positioned differently within the wall ofthe inner catheter 76 than shown in these illustrations. These twoballoons 180, 181 are oriented more or less perpendicular to theexpandable through return channel 124 and encircle the expandablethrough return lumen 124 with a toroidal shape. The most cephalicpositioned balloon 181 may be larger than the more caudal balloon 180 asit may be advantageous to seat the cephalic end of the device and thecephalic balloon in the right atrium. The portion of the inferior venacava between the right atrium and the hepatic veins 52 is typicallylarger than the suprarenal inferior vena cava (as was determined fromthe CT study performed by the inventor mentioned above), hence the needto provide a larger balloon or other sealing device cephalically. Sinceboth the proximal and distal balloons are oriented more or lessperpendicular to the axis of the through return lumen, the footprint ismuch smaller than the spherical balloon of the current prior art device,and therefore occlusion of the adrenal and renal veins will not benearly as problematic as with the current prior art device.

Alternatively, the elastomeric covering 97 may cover only a portion ofthe mesh braid as was will be discussed in FIG. 14. If this were thecase, a balloon structure (not shown) would essentially encircle orsurround the HVECC 94 to define it rather than the two toroidal balloons180, 181 of FIG. 6.

Moreover, the CT study demonstrated that the left renal vein 182 (inFIG. 7, which is a view of the device in the IVC from an anterior orcoronal perspective) was always positioned more cephalically than theright renal vein 183. It also demonstrated that accessory hepatic veins184 enter the IVC either ventrally or on the right side. Hence, it maybe advantageous to position the caudal toroidal balloon 180 at an angleas shown in FIG. 7 so that the HVECC 94 extends more caudally on theright to avoid occluding the accessory hepatic veins 184 and capture theaccessory hepatic venous effluent from HVECC 94, but more cephalicallyon the left to provide a safety margin against the inadvertent occlusionof the left renal vein 182 which can be positioned at nearly the sameaxial level as the most caudal accessory hepatic vein 184. Additionally,the cavoatrial junction is also frequently asymmetrical, and obliquedballoons may be utilized at both ends to better accommodate the uniqueanatomy present in the proximal and suprarenal IVC. Using an obliquedtoroidal balloon 810 in FIG. 7 overcomes the need for the proximal anddistal occlusion mechanisms, whether expandable braid or sphericalballoons, to be symmetric when there is in reality a non symmetricanatomy present.

The presence of the pump and filter outside of the body is inconvenientand creates additional steps as well. Placing the pump and filter withinthe recovery catheter and returning the filtered blood to the systemiccirculation without transporting it to an extracorporeal location may beaccomplished by miniaturizing the pumping and filtering components. FIG.8 shows a simplified view of a recovery catheter 76 similar to FIG. 6with the filter 43 and the pump 21 present within an extended section ofthe catheter 76. This extended section traverses the right atrium 200and into the superior vena cava 201. The presence of the pump 21 inclose proximity to the hepatic venous effluent collection area 94 hasthe added benefit of creating a negative pressure region within thehepatic venous effluent collection area 94, further guarding against anyleak into the systemic circulation, as if there is lower pressure in thehepatic venous effluent collection 94 area than in the IVC 99, therewould be no chance of leakage into the higher pressure of the IVC. Thepump 21 may be one of three general types of pumps that are able topropel blood, i.e., roller, centrifugal, and axial pumps. Of thesetypes, a centrifugal pump may likely be best suited for this applicationas they generally cause less hemolysis than the other types, and can bemore easily miniaturized. Centrifugal pumps consist of a nonocclusivepump head and various numbers of impeller blades positioned within avalveless pump housing usually powered electromagnetically. Pumprotation generates a vortex resulting in nonpulsatile unidirectionalblood flow and high flow rates can be achieved, although the centrifugalpumps can bridge a limited pressure differential. In the intended usewithin this invention, there is venous to venous flow which does notdemand a significant pressure differential. Several companies currentlyproduce centrifugal pumps including Medtronic, Sarns, and St. JudeMedical, amongst others. Pumps developed for neonatal use may bemodified for use in the current application. Axial pumps consist of arotor type impeller housed in a small casing and mechanical action ispowered by an electromagnetically powered rotor system. An example isthe Impella pump from Impella Cardiotechnik AG, or even the MicroMedDeBakey VAD. The pump 21 only may be placed in the catheter in anotherembodiment (not shown) with the filter 43 remaining extracorporeal.

The filter 43 for the example of FIG. 8 may be any one of several typesincluding but not limited to electronic, cartridge, membrane,microtubular, microfluidic, magnetic, chemical, activated carbon,positively or negatively charged filter components, and others. Thefilter element can be produced from any suitable media such as carbonbased or synthetic media which can extract a drug from blood byadsorption or binding drug molecules to porous structures, anionexchange, particulate filtration, aggregate filtration and so forth.Filter structures can be hollow fiber membrane, semi permeable membrane,granular media, woven or non woven filter fabrics or other suitableforms. The filter may be expandable (not shown) after it has beeninserted especially if the efficiency of the filter is dependent on thesurface area of the filter, preferably in the superior vena cava 201 orright atrium 200 allowing the filtered blood to be returned to thesuperior vena cava 201 or right atrium 201 without being transportedextracorporeally. In the case of an activated carbon filter, theabsorption efficacy may be different for several different types, i.e.,ROX, UKR, CLA, amongst others, of activated carbon as well as shape andsurface morphology. The particles may be coated with a polymethylmethacrylate co-polymer, or some other material, at differentthicknesses and with different methods to diminish the effect on redblood cells and other blood components. Frequently there may be a tradeoff between coating thickness and absorption efficiency. Another type offilter that may be used is one that contains porous hollow fibers whichmay be coated with affinity agents, or the affinity agents may be eitherwithin or outside the hollow fibers. The blood can be pumped eitherthrough the porous hollow fibers, and the substance to be removed isselectively transported to the space outside the hollow fibers, orconversely, the blood may be pumped through the spaces outside thefibers and the substance to be removed is selectively transported to theinterior of the hollow fibers.

Another type of blood filter is a microfluidic blood filter. Used withthe current device, the chemotherapeutic agent would be infused andcollected as previously described in FIG. 8, but upon entering therecovery lumen 76 the blood containing the chemotherapeutic agent wouldbe admixed with coated iron oxide beads that are coated with an affinityagent. The chemotherapeutic agent would adhere to the coated beads andbe pumped with the blood through to the filter 43 where an electromagnet(not shown) would separate the beads and chemotherapeutic agent from theblood. Given the space restraints of an in-catheter filter, this systemhas advantages as it may obviate the bulk required by traditionaldesigns. A hybrid filter may also be used which employs one or more ofthe different filter types within the same device.

The filter 43 may be expanded by the pressure of the pump 21, or byother means. The blood from the hepatic venous effluent chamber 94 wouldenter the recovery catheter 76 via apertures 95 as in several otherembodiments and proceed cephalically in the extended segment of therecovery lumen 76, through the pump 21 and the filter 43 and exit intothe superior vena cava 201 or right atrium 200 through the distal end ofthe device. A side hole 203 may be provided in the recovery catheter 76for the exit of the stiff actuator rod 154. Alternatively the actuatorrod 154 may be attached to a separate actuator sleeve (not shown)located exterior to the recovery catheter 76 that is attached to thetubular braid in this location and would be slideable relative to therecovery catheter 76, so that retraction of the actuator rod 154 wouldmove the separate actuator sleeve (not shown) to expand the braid andadvancement of the actuator rod 154 would move the separate actuatorsleeve (not shown) to collapse the braid.

Even another embodiment (not shown) utilizes a self expanding returnchannel 124, and toroidal shaped balloons 180, 181 as in FIG. 6, butwithout the active expansion system as in FIGS. 6 and 7. While theactive mechanical expansion assistance provides a control not found inpurely self expanding systems, the expansion assistance provided byinflating the balloons combined with a self expanding mechanism of thethrough return lumen may provide enough radial strength to maintainpatency of the through return lumen in this embodiment. The sealingfunction will be provided by the balloons, hence some of theobjectionable qualities of a self expanding system listed previously arenot as pertinent if the self expanding component is just the throughreturn lumen as is the case in this particular embodiment. The functionand components of this embodiment are otherwise essentially the same asin FIGS. 6 and 7.

Other Recovery Catheter Assemblies

FIG. 9 shows another example of a recovery catheter assembly 136including a recovery device 138. Recovery device 138 includes a funnelcatheter 50 that covers the ostia 51 of the hepatic veins 52, isolatesthe hepatic venous effluent and retrieves the hepatic venous blood intothe catheter 53 or tubing to be pumped into the filter 43 and returnedto the body as in FIG. 1. The funnel catheter 50 is held in place by atemporary retrievable balloon expandable strut 54 provided on a separatevenous catheter 55 securing it over the hepatic venous ostia 51. Balloonexpandable strut 54 includes a mesh of struts 77 defining an openarchitecture 79. The length of temporary retrievable strut 54 is longerthan the funnel catheter 50 by design as this will further secure theends of the funnel catheter to the ventral inferior vena cava 56. Thestrut 54 also compresses the periphery of the funnel 50 assuring a tightseal against the ventral aspect of the inferior vena cava 56. Thesurface of the strut 54 compressing the funnel 50 may be indented orhave a concavity 58 so as to not obstruct the funnel 50. The openarchitecture 79 of the strut 54 will not obstruct venous inflow from therenal or adrenal vein even if it covered them. This design solves thetwo problems of the prior art device mentioned above, the occlusion ofrenal/adrenal veins and the lack of an adequate through return channelfor IVC blood. The temporary strut 54 forces the funnel catheter 50(which is obliquely shaped) against the ventral aspect of the proximalIVC 56 securing it over the hepatic venous ostia 51 without occludingrenal/adrenal veins. The funnel catheter 50 occupies very little annularspace in the IVC 56 allowing blood to flow freely from the mid anddistal IVC 56 into the right atrium through the spaces or interstices 59in the temporary strut 54 when the balloon 60 on the temporary strut 54is deflated.

FIGS. 10A and 10B demonstrates the funnel catheter 50 in more detail. Itis composed of two shafts 61, 62 and a mesh braid 63 of nitinol (orother appropriate biocompatible material) covered with a siliconeelastomer (not shown) or other substance that is expansible andresistant to degradation by the chemotherapeutic agent. Unique to thisapplication, however, the two shafts 61, 62 of the funnel catheter 50are obliquely angled at their distal ends 64 so that the funnel 50projects to the side of the catheter rather than directed distally inthe prior art funnel catheters. In FIG. 10A, the inner shaft 61 isretracted in respect to the outer shaft 62. This keeps the mesh braid 63of the funnel 50 within the lumen of the outer shaft 62. The mesh braid63 is bonded to both the inner shaft 61 and to the outer shaft 62. Asthe inner shaft 61 is retracted, the mesh braid 63 forms a cylindricalchannel parallel and within the channel formed by the outer shaft 62. Asdemonstrated in 10B, when the inner shaft 61 is advanced distally towardthe ends of both shafts, the mesh braid 63 is propelled out the distalend of the outer shaft 62 and forms a funnel 50. Moreover, the shape andthe strength of the funnel catheter 50 can be affected by addinglongitudinal, horizontal, and oblique lay ins. The shape memoryproperties of nitinol and the ability to place these lay ins withspecific properties at specific locations within the braid allows abraid configured device to be tailored to the specific application. Thecombination of nitinol combined with brading technology essentiallyassures that most any shape is possible. In fact the description in thisparagraph of forming a shape to cover the hepatic vein orifices isdifferent than previous methods, which are all a funnels projectingdistal to the end of the catheter. This construction may be used inother examples discussed herein.

FIGS. 11A, 11B, and 11C represent the retrievable temporary balloonexpandable strut (RTBES) 54. In FIG. 11A, the strut 54 is expanded overthe inflated balloon 71. The catheter contains two shafts, and outer one73 and an inner one 76. The balloon is attached to the inner shaft 76and the RTBES 54 is attached to the outer shaft 73 via a bond 77. Distalto the balloon 71 the braid 77 of the strut 72 is bonded 69 to the innershaft 76 as shown.

FIG. 11B demonstrate the balloon 71 to be deflated while the strut 54 isexpanded. Forward force (arrows) on the outer shaft 73 with respect tothe inner shaft 76 will assist in keeping the strut 54 expanded againstthe wall of the IVC (not shown) and the funnel catheter (not shown.) Theinterstices 79 of the strut 54 provide more than adequate space forblood to flow from the IVC into the right atrium. The pressure from thestrut 54 forces the funnel catheter 50 against the ventral IVC andsecures it in place over the hepatic venous ostia 51. The RTBES 54 maybe inserted via the internal jugular vein or the femoral vein, as maythe funnel catheter, but usually the two would be inserted throughseparate veins. Moreover, the shaft 76 of the RTBES 54 may be utilizedas the return conduit after the hepatic venous blood has passed throughthe filter, as it would serve no other purpose while the hepaticinfusion was being performed. If utilized in this manner, it would bepreferentially inserted via the internal jugular vein. Additionally, theshafts 73, 76 of the RTBES 54 may have openings (not shown) into thelumen along the shafts 73, 76 so some of the returning blood would bedirected into the superior vena cava.

In FIG. 11C, the outer shaft 73 is retracted (arrows) with respect tothe inner shaft 76 collapsing the strut 54 over the balloon 71, as theouter shaft 73 is bonded 77 to the strut 54 proximally and the innershaft 76 is bonded 69 to the strut 54 distally. This will allowinsertion and removal of the device 55 in a low profile.

FIG. 12 is a cross section of the two shafts 73, 76 of the device 55proximal to the balloon 71 and strut 54. It demonstrates the inner shaft76 and outer shaft 73. The inner shaft 76 comprises a large lumen 68 andat least one smaller lumen 67 for inflation of the balloon. Anotherlumen 66 may be present for insertion of a guide wire (not shown) or forinjection of contrast. Contrast may be injected also through the space65 between the inner shaft 76 and outer shaft 73.

FIGS. 13B and 13C discloses a retrievable self expanding or balloonexpandable mesh braid structure 80. It may be delivered and retrievedthrough a funnel catheter 81, see FIG. 13A, which is likely to bedissimilar to the funnel catheter 50 in FIG. 10. The funnel catheter 81may be a simpler design in that occlusion or isolation is not requiredof the funnel catheter in this configuration and the funnel 82 at thedistal end of the catheter is directed along the axis of the shaft ofthe catheter. The funnel catheter may not be even needed in fact.

In FIG. 13B, the isolation apparatus is a retrievable self expanding orballoon expandable mesh braid structure 80 covered with an elastomericmaterial (not shown) resistant to the chemical properties ofconcentrated chemotherapeutic agents, such as, but not limited tosilicone. The elastomeric covering (not shown) may cover all of thistubular structure 80, or, in a preferred embodiment, only the ventralhalf. This latter configuration would preclude obstruction of renal oradrenal veins. In this particular configuration, the isolation chamberapparatus is a tubular mesh braid structure 80 with a side arm 83 thatis inverted into the main lumen 84 of the structure 80. This invertedside arm 83 is bonded 85 to the recovery tubing 86 that transports thehepatic venous effluent to the exterior of the body where it is pumpedthrough the filter. Alternatively, the recovery tubing 86 may beattached similar to the recovery lumen 76 of FIG. 4. Also shown are thetether wires 88 attached to the structure 80 so that it may be withdrawninto the funnel catheter 81 for removal. Instead of the inverted sidearm, the mesh braid structure 80 may be alternatively attached to therecovery lumen 83 as demonstrated above in FIG. 4.

As shown in FIG. 13C, the ventral aspect of the retrievable tubularstructure 80 containing the inverted side arm 83 contains a concavity 87large enough to cover the ostia 51 of the hepatic veins 52 as well as toserve as a small reservoir to direct the hepatic venous effluent throughan orifice 88 into the inverted side arm 83 and the recovery tubing 86to the exterior. This configuration provides effective hepatic venousisolation as well as a very generous through return channel for IVCblood to pass to the right atrium, solving the major problems of theprior art device.

FIG. 14 demonstrates a retrievable isolation apparatus 90 in which thetubing 91 to the exterior is bonded (not shown) directly to the wall ofthe apparatus 90 vs. the more flexible inverted side arm 83 as in FIG.12. The wall of the retrievable isolation apparatus 90 has a concavity93 that covers the hepatic venous ostia 51 and serves as a smallreservoir 94 to direct blood into the tubing 91 through an orifice 95.The other properties are similar to those in FIGS. 8B and 8C. In bothinventions of FIGS. 8B, 8C and 9, there may be provided additional layeror layers of the elastomeric material 96, or even a balloon structure(not shown), about the collection chamber to enhance the seal. A specialbraiding technique of the braid (not shown) may also enhance the seal atthese locations. Since the hepatic veins enter the IVC either ventrallyor on the right side, the elastomeric coating may be limited to theselocations rather than being circumferential. Additionally, in theexamples of the devices in FIGS. 8 and 9 in which the elastomericmaterial 97 covers only the ventral and right side aspect of theapparatus, the additional sealing method 96 described above mayessentially encircle the concavity described above to provide moreeffective sealing. The tether wires 99 are also shown.

Additionally the expandable mesh braid with the elastomeric coating 97may contain a funnel shaped structure (not shown) on both ends toprovide isolation of the hepatic venous blood. The ends may be comprisedof a self expanding material (not shown) such as Nitinol that wouldcause the ends to flare out and contact the IVC wall with an exaggeratedamount of force to provide an extra sealing property.

FIG. 15 demonstrates another configuration which is similar inconstruction to FIGS. 11A, 11B and 11C in that a retrievable temporaryballoon expandable strut (RTBES) 98 is utilized. However the RTBES 98 isnot utilized to compress the funnel catheter 50 against the ventralaspect of the IVC in this particular configuration. The RTBES 98contains the collection chamber 101 which functions as the funnelcatheter 50 did in the prior example. This RTBES 98 expands by inflatinga balloon 71 and contracts by manipulating the inner shaft 76 and outershaft 73 as demonstrated in FIGS. 6A, 6B, and 6C. At least the ventralaspect of the strut 98 is covered with an elastomeric material 97,although the elastomeric material may cover all of the structure exceptfor the distal and proximal ends, and may have an extra layer 96 ofelastomeric material at least partly encircling the collection chamber94, as in FIG. 14. The shape of this and other configurations can becontrolled by braiding technology, the use of lay ins, and so forth. Thehepatic venous collection tubing 91 may be directed extracorporeal as inthe prior examples, but may alternatively be directed to and bonded tothe distal aspect of the inner lumen 76 as is shown. The cross sectionalview of FIG. 12 would apply in this instance and the hepatic venousblood would be directed through the large central lumen 68.

FIG. 16 demonstrates even another configuration in which a retrievableself expanding mesh braid device 110 with an elastomeric covering 113 isutilized. This double funnel 114 configuration in which the ends 114 ofthe device 110 flare out more than the central section. The centralportion of the device 110 would be bonded to the recovery catheter 112with at least one, but preferably several orifices 111 in the recoverycatheter 112. The added pressure at the ends would create an effectiveseal, isolating the hepatic venous effluent and directing it into theorifices 111 connecting to the recovery catheter 112. Tether wires 115on the proximal end of the device 110 may be attached to the shaft ofthe recovery catheter 112 or may be bonded together to form a singletether wire (not shown) for removal of the device 110. In this example,the recovery catheter 112 extends through the entire length of thedevice 110 to give some rigidity and pushability to the device forplacement, manipulation, and removal purposes. It may not extend theentire length of the device 110 however.

The braiding technique will typically create more expansile braid at theends of the structure and less expandability in the central portion.Welds of the filaments in the center of the braid may be utilized tocreate a center section that is smaller than the distal ends as may theinsertion of horizontal lay ins. The bonding of the orifices 114 in theventral aspect of the device 110 will also help create a small reservoirin the central portion for the hepatic venous effluent. The funnelshaped ends will have a smaller footprint than the expanded balloons inFIGS. 1, 2, and 3 prior art devices, and should not occlude the renalveins. However, about the dorsal aspect of the distal end of the device110, a section of braid 123 may not be coated with the elastomericcoating 113. This would allow blood from renal or adrenal veins to flowinto the return through channel 124 through the open mesh.

There may or may not be radiopaque markers at the end 117 of therecovery catheter 112, the distal end of the device 118, and theproximal end 119 of the device 110. Alternatively markers (not shown)may be on the device 110.

The device 110 will typically be delivered and removed through a funnelcatheter 120 which is a mesh braid 122 with an elastomeric coating 113housed within a outer sheath 121. In deployment the outer sheath 121containing all of the components above would be inserted in the femoralor internal jugular vein and, in the case of the internal jugular veininsertion, the tip positioned just below the most caudal hepatic vein.While keeping forward pressure on the recovery catheter 112, the outersheath and the funnel catheter 120 would be withdrawn together deployingthe device 110 as shown in FIG. 16. The proximal end would be cephalicto the most cephalic hepatic veins. The hepatic artery would be infusedwith a selected agent, and hepatic venous blood collected in therecovery catheter 112 through the orifices 114 and pumped through thefilter outside of the body, and returned to the body as in FIG. 1.Alternatively, the filtered blood may be returned to the body throughthe funnel catheter 120. At the termination of the procedure, the outersheath 121 would be withdrawn from over the funnel catheter 120 exposingthe funnel 120. The device 110 then would be withdrawn through thefunnel catheter 120 by withdrawing the recovery catheter 112. When thedevice 110 was within the funnel 120, the funnel 120 containing thedevice 110 would be withdrawn into the outer sheath 121, and the entireapparatus removed. Again a generous through return lumen has beenprovided, an effective collection chamber is present, and means areprovided to prevent occlusion of the renal and adrenal veins.

Even another configuration of this apparatus (not shown) utilizes aexpandable funnel to occlude the IVC caudal to the most caudal hepaticveins similar to FIG. 16 and a balloon to occlude the upper IVC justbelow the right atrium. In other words, the flare 114 of FIG. 16 may bepresent on the caudal end, that is to the left, in FIG. 16, and aballoon structure (not shown) may be present on the cephalic end. Thecentral lumen which serves as the return through channel to return IVCblood to the right atrium may be a self expanding braided segment withan elastomeric coating that is similar to that of FIG. 16. The hepaticvenous blood that flows into the hepatic venous collection tubing doesnot have a separate channel within the isolated segment as in the priorart devices of FIGS. 1, 2, and 3. The hepatic venous effluent collectsin a space outside of the expandable through return channel and directedinto the recovery catheter which is directed through the balloon on thecephalic end in one iteration. The balloon inflation lumen may becontained in the wall of the shaft of the hepatic venous collectiontubing as previously discussed. The cephalic end of the central returnlumen in the right atrium may have openings to allow the IVC blood toexit this central lumen or may be comprised of the mesh braid withoutthe elastomeric coating, the IVC blood flowing through the intersticesof the braid. In this configuration, the funnel distally will provideocclusion of the IVC and effective isolation of the hepatic venoussegment of the IVC with a very small footprint, obviating occlusion ofthe renal and adrenal veins, while the combination of the funnel shapeof the caudal orifice of the expandable segment of the through returnchannel combined with the expanded through return channel will provide avery adequate conduit for blood to flow freely from the IVC to the rightatrium. This configuration is a viable alternative to the prior artdevices. The use of a balloon recognizes the fact that while the funnelshaped occluders will perform better than balloon occluders in mostinstances because of several reasons including the instant on/instantoff capabilities, the much smaller footprint, larger through lumens,etc., that there may indeed be a need at the junction of the IVC and theright atrium to occlude with a large footprint.

The above method also has the benefit of creating a moderate degree ofobstruction in the upper IVC, which may create increased pressure in theIVC vs. the hepatic venous effluent collection area. Obviating theobstruction to the returning blood is one of the main goals of thecurrent invention as too much obstruction will cause a drop in bloodpressure, etc., as described above. However, creating a controlledmoderate amount of obstruction may be desirable to increase the IVCpressure above that in the hepatic venous effluent collection area so asto prevent leakage of the hepatic venous effluent into the IVC. Thiscould be accomplished by a balloon or by other means incorporated intothe design of the device, for example a baffle type device that iscontrolled by the operator. Pressure sensors may be provided within theupper IVC and within the hepatic venous effluent collection chamber tomonitor the pressures of the two areas with or without the baffledevice. This would be accomplished by providing wires along the cathetershaft(s) or by utilizing wireless pressure sensors. In this particularconfiguration, it is imperative that the seal about the hepatic venouseffluent collection chamber prevent leakage not only from that chamberinto the IVC or systemic blood, but also from the IVC into that chamber.

It should be noted that the pressure sensors would detect the pressureof the hepatic venous effluent and at least one pressure reading in theIVC or right atrium. By connecting the pressure sensors to a controllerand the controller to the extracorporeal pump, the pump could beregulated to always have a lesser pressure in the hepatic venouseffluent than in the IVC. If the pressure in the hepatic venous effluentbecame close to the pressure in the IVC, or even exceeded the pressurein the IVC, then the controller would speed the pump so that more bloodwas withdrawn from the hepatic venous effluent collection chamber,thereby diminishing the pressure within that collection chamber to alevel safely below that in the IVC. This would ensure that there couldbe no leakage of hepatic venous effluent (lower pressure) into thesystemic IVC (higher pressure,) If there was any leakage at all, itwould be from the IVC into the hepatic venous effluent collectionchamber, and this would not be harmful. The adjustment of the pressureby controlling the speed and output of the pump could be doneautomatically with the controller, or alternatively with a manualadjustment of the pump speed by the operator or an assistant who ismanually monitoring the pressures hepatic venous effluent collectionchamber and the IVC and/or right atrium. Alternatively, the pump couldbe programmed to run at a speed, or regulated by the controllerutilizing a single pressure sensor, that would effectively keep thepressure in the HVECC, either by direct measurement or by extrapolatedmeasurement, less than 1-2 mm Hg (the normal pressure in the rightatrium) or thereabouts. This would insure that the pressure in the HVECCwas less than the pressure in the IVC/RA, and hence there could be noleakage from a lower pressure system into a higher pressure system. Insome examples the pressure in the IVC is taken manually before theprocedure so that there would be needed only one pressure sensorproximal to the pump to control the pump speed and keep the pressure atthis sensor less than the IVC pressure determined at the beginning ofthe procedure.

Still another alternative method (not shown) utilizes two balloons asthe occlusion elements, both caudally and cephalically, but the throughreturn channel is expansile by means of a catheter as in FIGS. 11A, B,and C. This would take advantage of the proven occlusion features of theballoons, but the expansile through return channel would provide achannel large enough to return the IVC blood to the right atrium withoutthe rather meager lumen of the current device. The struts on thecatheter of FIGS. 11A, B, and C would compress the inner circumferenceand inner wall of the balloon outward creating more annular space andlumen within the central open area of the balloon. The hepatic venouseffluent is collected in the space isolated by the two balloon occlusionelements, and then transported to the exterior of the body. This may bedone by a separate catheter lumen or through the main lumen of thecatheter of FIGS. 11A, B, and C.

A modified version of the embodiment (not shown) described in the aboveparagraph would utilize a self expanding apparatus to create theexpansile through return channel within the center or “donut hole” ofthe balloons. It would be similar to the embodiment of the aboveparagraph, but the struts would expand without the use of a thirdballoon. The occluding balloons would be compressed from their innercircumference, enlarging it so as to provide an adequate throughchannel. A balloon configuration with an enlarged central channel hasbeen termed a toroidal balloon. A toroidal balloon structure on each endof the device to define the limits of the hepatic venous effluentcollection chamber (HVECC) may be combined with a self expandablestructure such as a mesh braid or other self expandable structure andmounted on a catheter 73 as shown in FIG. 4 and FIG. 6. The balloons(not shown) would either augment or replace the flares 131, 132 in FIG.4 or be placed as in FIG. 6 or FIG. 7. Otherwise this modified versionwould be generally similar to FIG. 6.

Another completely separate method of performing perfusion of an organwith a toxic substance and collecting the venous effluent, whileproviding for blood flow would be to utilize the prior art device or onesimilar that does not have an adequate through return lumen, but to adda second additional catheter system and, if necessary, a pump totransport blood from the lower IVC, or some other region,extracorporeally and then return it to the systemic circulation beyondthe point of collecting the venous effluent, usually the superior venacava. This would essentially create an extracorporeal bypass circuit andlikely be functional, although problematic because of the addedcatheters, punctures, pump, equipment and so on. A special returncatheter (not shown) may have two return lumens: one for the hepaticvenous effluent which has been filtered and another for the systemic IVCblood which has been routed extracorporeally around the obstructioncreated by the use of the prior art type devices. This would obviate theneed for two return catheters. The current inventions solve the problemof lack of an adequate through return channel without resorting to thisrelatively cumbersome method.

To prevent movement or migration of the device during infusion, anattachment mechanism (not shown) at or near the skin insertion site maybe provided. It may vary in configuration from a suture attached to thetissues, to a clip at the skin level, to an anchoring device, or anyother means of preventing movement of the catheter.

The methods of utilizing all of the above examples are quite similar.Imaging studies such as CT scans, MRI, or others are utilized to measurethe distance between the most cepahalad placement of the flared blockingelement, whether it be the cavoatrial junction or the supradiaphramaticIVC, and a point just above the renal veins. Measurements are also takenof the dimensions of the IVC. An appropriately sized recovery device,such as the device 138 of FIGS. 4-8 of the current invention is chosen.Typically, a catheter is placed in the hepatic proper artery from afemoral puncture for subsequent perfusion of the liver by a concentratedhigh dose substance. The device of the current invention, in oneconfiguration or the other, is placed in the IVC and deployed so thatthe isolation apparatus covers the hepatic venous ostia. The morecephalic end of the device may be placed in the right atrium or in thesupradiaphragmatic IVC which is normally 1-3 cm. in length. In the caseof the flared configurations of some of the embodiments, the distalflares may abut more force radially against the wall of thesupradiaphragmatic IVC and the sealing annular force directed toward thewall of the IVC than if the device were placed in the right atrium andtraction on the device at the cavoatrial junction utilized to produce aseal. Testing is done to determine if the placement is appropriate byinjection of contrast in a retrograde manner through the recoverycatheter and into the HVECC, and demonstrating that there is no leakagefrom the isolated segment. Contrast is injected into the distal IVC todetermine that there is good return through flow to the right atrium.Testing will also evaluate the status of the renal veins and adrenalveins, and the device adjusted to provide for flow from these veins.Hepatic venous effluent will be collected, and the hepatic arterialinfusion will begin. The venous effluent will be pumped and filteredextracorporeally and returned to the body as in the prior art devicesfor a period of time. After the arterial infusion is complete the venouseffluent collection and treatment will continue for a prescribed periodto prevent any delayed washout of the concentrated high dose substancefrom the liver into the systemic circulation. After a period of time,the chosen device will then be collapsed, retracted, and removed fromthe body.

In the cases where the approach is done preferably from the internaljugular vein, it anticipated that flush injections of contrast throughthe filtered blood return catheter that would be present in the femoralvein would be done to roadmap the anatomy, and could be donesimultaneously with the placement of the apparatus as the blood wouldflow centrally toward the heart. A side arm on this catheter wouldprovide a means of injecting contrast while the filtered blood returnflow is maintained. This would be valuable to monitor the placement ofthe apparatus during the procedure and is not feasible with the currentprior art devices.

It should be noted that features of the particular configurations listedabove may be used with other configurations interchangeably to provide asmaller footprint of the isolation chamber in the IVC and to provide foran adequate return through lumen for IVC blood to return to the rightatrium. While the devices described here have particular use in theinferior vena cava, use elsewhere in the body is also anticipated.Moreover, while the recovery of hepatic venous effluent has beendescribed, reversing the flow through the recovery catheter apparatusmay be done to deliver a drug or drugs or other substances in aretrograde manner to the liver via the hepatic veins or other tissues.

While the above descriptions of the funnel catheter and the isolationapparatus and the through return lumen describe the use of mesh braid asthe supporting and expandable component of the particular configuration,other options are to be covered by this patent application, such ascross linking, spiral support configurations, strut like configurations,more or less parallel wires or support members, non-parallel wires orsupport structures, folded configurations, circumferential balloons,partially circumferential balloons, spiral balloons, abuttingstructures, and others.

In the case of treatment of cancers, tumors, infections, or conditionsinvolving other organs which may have only one or two or a few veinsdraining that organ, there may be no need to occlude the vena cava. Thesimple insertion of a funnel catheter directly into the ostium of thevein(s) of that particular organ would serve to collect and isolate thevenous blood from that organ. The funnel catheter, whether constructedof mesh braid or other materials, is a simpler, easier, safer, morestable and quicker method of isolating and collecting the venouseffluent than balloon based catheters, and occlusion of a vein for thecollection and isolation of venous effluent by any funnel catheter isexpressly covered in this patent application.

In fact, the perfusion of a focal anatomic area whether it be anextremity, abdominal, thoracic, cervical, or cranial area, or other softtissue or bone area with any substance in a concentration that wouldcause toxic effects in other areas of the body, and collection of thesubstance with a system that either does not use a balloon or providesfor a expandable through channel is part of this application. Forexample the substance could be an antibiotic to treat a focal infection,an anti-tumor drug, a thrombolytic agent to dissolve clot, a substancethat converts vulnerable plaque to stable plaque, or dissolve plaque,stimulates cellular growth, retards cellular growth, relieves pain,causes tissue atrophy or cellular apoptosis, causes lipolysis, causeshair growth or loss, improves or alters hearing, vision, taste, smell,and touch senses and the like. For example, the focal area or organcould be the brain, salivary gland, thyroid gland, lymph nodes, softtissue, lungs, heart, spine, bone, kidney, ovary uterus, breast,extremities, digestive tract, nasal area and sinuses, eyes, ears, antthroat.

The local perfusion of an area of tumor with a highly concentratedsubstance may indeed be the first line of treatment in the future forthe treatment focal malignancies to shrink if not obliterate the tumor.Surgery could then be done on the much smaller tumor, if indeed therewere any tumor left.

In the case of organs that have only one or two veins, or organs wherethe venous drainage may be approached by several catheters that areplaced directly in the ostium or ostia, the funnel catheter 113 designshown in FIG. 16 may be utilized. Another design for a funnel catheteris shown in FIG. 13A. The highly concentrated substance would beperfused into the artery of the organ, and the funnel catheter used forrecovery of the venous effluent. The venous effluent would be pumpedthrough the filter and returned to the systemic circulation aspreviously discussed. The action of the funnel in this particularembodiment may be controlled by moving inner and outer actuator sheaths61 and 62 as in FIGS. 10A and 10B. The ends of the two actuator sheaths61, 62 are angled in FIGS. 10A and 10B causing the funnel in thatillustration to project to one side. With actuator sheaths having endsthat are not angled, the funnel will project straight ahead from theends of the two actuator sheaths with a shape demonstrated in FIGS. 13Aand 16. This will allow the funnel catheter to be placed within theostium of the organ being treated. Because of the mechanical action ofthe funnel caused by the two actuator sheaths as in FIGS. 10A and 10B,the funnel will exert radial force against the wall of the vein justinside the ostium and the braid will further anchor the funnel withinthe vein.

Organs that would be amenable to this approach include the kidneys,pelvic organs, extremity, brain, lung, breast, and various abdominalorgans by placing the funnel catheter in the portal vein, amongstothers. The artery serving that organ would be catheterized and thesubstance infused. A catheter for collection of venous blood using aballoon on the end to occlude or block the vein in question works fairlywell, although is not as stable as desired, mainly because of itsspherical shape. Balloons tend to slide within the vessel, and there isa much greater probability of a balloon occlusion collection catheter toslide out of the venous ostium that there is of the funnel catheterdescribed above. The mesh braid creates a slightly irregular surface onthe funnel which resists slippage along the venous wall without damagingthe intima.

Moreover, the shape of the funnel is advantageous for another reason.Typical balloon catheters have an opening at the end of the straightcylindrical catheter just distal to the balloon. The venous effluentmust be withdrawn through this end hole, and since it is desirable tokeep the pressure in the draining vein less than the vein it is draininginto, suction will be applied by the pump creating suction within thisrecovery catheter. With a single end hole, there is the possibility ofthe suction not only creating turbulence and resulting hemolysis, butalso the possibility of causing the vein wall to occlude the single endhole because of the suction. The funnel catheter overcomes theseproblems by providing a smooth transition from a large diameter veininto the much smaller catheter, minimizing turbulence and hemolysis, andobviating obstruction of the catheter by the suction. Additionally, inrecovering venous effluent from these single vein organs, it isimperative that any drainage through collateral veins be minimized orcompletely eliminated. Many venous collaterals exist, but only flow whenthere is increased venous pressure within the organ for some reason oranother. Hence, having a catheter that can maintain a good deal ofsuction to keep the venous pressure low in the effluent vein and theorgan is important in preventing collateral flow around the recoverysystem and leakage into the systemic circulation.

Certainly, the effectiveness of the seal about the recovery deviceacting as an isolation apparatus is paramount to prevent highconcentrations of a deleterious substance from entering the systemiccirculation. Since the free hepatic venous pressure is only 1-5 mm Hg.greater than the pressure in the upper IVC or right atrium, the sealdoes not have to be the same as that which might occlude arterial flowwith pressure differentials of 100-200 mm Hg. However, it is imperativethat no leakage occurs from the hepatic venous effluent chamber into theIVC. Testing the effectiveness of the seal may require frequentinjection of contrast agent which is time consuming and not veryaccurate. An alternative method of detecting any leakage of the toxicsubstance would be to develop a real time assay of the toxic substance,and test systemic blood periodically. Alternatively, a substance that iseasily assayed could be injected with the toxic substance into thehepatic artery. It would then be collected with the hepatic venouseffluent along with the toxic substance and transported externally,where a separate filter (in line with the filter that filters the toxicsubstance) or the same filter would filter the easily assayed substanceout of the blood to be returned to the body. Therefore, assays ofsystemic blood of the easily assayed substance would determine if theseal about the isolation apparatus was functioning properly. The easilyassayed substance is filtered out of the returning blood, so if therewas any activity in the systemic circulation, then it would alert theattending physicians that there was a high probability of a leak of thetoxic substances into the systemic circulation. The easily assayedsubstance may be have the properties of methemoglobin or carbonmonoxide, or any other substance for which there is a simple, quick, andeasy assay, and also be a substance that is easily filtered.

It is apparent that the materials comprising the device must possessflexible, expandable, contractible, amongst other, characteristicsincluding the ability to conform to different shapes and sizes withinthe same patient with enough annular force to effect a complete seal.The variety of shapes encountered in the IVC are much more varied thanin the typical artery which has a more or less round shape and usuallyconsistent, although occasionally minimal tapering, diameter throughoutthe area being treated or manipulated. While the pressures needed toseal the HVECC are less than the arterial system certainly, the need forthe device to conform to different sizes and shapes in the same patientis of great importance in constructing a device for use in theretrohepatic IVC. The construction of the different embodiments of thecurrent invention will utilize designs, materials and techniquesspecifically adopted to venous use and different than those devicestypically utilized in arteries.

Compared to prior art isolation apparatus, recovery device 138 canachieve a smaller footprint as well as a larger through return lumen.Some examples of recovery device 138 can be made with either anadjustable length or different length devices may be used.

Any and all patents, patent applications and printed publicationsreferred to above are incorporated by reference.

Modifications and variations can be made to the disclosed embodimentsand examples without departing from the subject of the invention asdefined in the following claims. For example, while the above examplesand embodiments use separate mechanical actuators to expand the proximaland distal blocking elements, in some cases a single mechanical actuatorcould be used to the same effect; one such mechanical actuator could bea balloon housed within the recovery device having enlarged proximal anddistal ends when expanded.

What is claimed is:
 1. A recovery catheter assembly comprising: a firstactuator element; a second actuator element; a mechanically radiallyexpandable and contractible recovery device operably connected to thefirst actuator element and the second actuator element, the recoverydevice having a proximal end operably connected to the first actuatorelement and a distal end operably connected to the second actuatorelement; the recovery device comprising: proximal and distal blockingportions at the proximal and distal ends thereof; and a central portionbetween the proximal and distal blocking portions; the recovery deviceat least partially placeable in a first, radially collapsedconfiguration and in a second, radially expanded configuration bymanipulation of the first actuator element and the second actuatorelement so that when in the second, radially expanded configuration theproximal and distal blocking portions have radial dimensions greaterthan the radial dimension of the central portion thereby at leastpartially defining a collection chamber at the central portion, themanipulation of the first actuator element and the second actuatorelement comprises movement of the first actuator element and the secondactuator element with respect to the recovery device.
 2. The assemblyaccording to claim 1, wherein the recovery device is fully placeable inthe first, radially collapsed configuration, and in the second, radiallyexpanded configuration, by manipulation of the first actuator elementand the second actuator element.
 3. The assembly according to claim 1,wherein the recovery device comprises a mesh braid.
 4. The assemblyaccording to claim 3, wherein the recovery device comprises a proximalwire set securing the proximal end to the distal portion of the firstactuator element, and the proximal wire set comprises a plurality ofradially and axially extending elements, said radially and axiallyextending elements being extensions of said mesh braid.
 5. The assemblyaccording to claim 3, wherein the recovery device comprises a proximalwire set, securing the proximal end to the distal portion of the firstactuator element, and a distal wire set, securing the distal end to theproximal portion of the second actuator element, each of the proximaland distal wire sets comprises a plurality of radially and axiallyextending elements, said radially and axially extending elements beingextensions of said mesh braid.
 6. The assembly according to claim 3,wherein the collection chamber is defined by the proximal and distalblocking portions and the central portion comprises an elastomericmaterial on said mesh braid.
 7. The assembly according to claim 1,wherein: the recovery device comprises proximal and distal toroidalblocking balloons at the proximal and distal ends of the recoverydevice; the recovery device is placeable in the first, radiallycollapsed configuration when (1) the blocking balloons are in deflatedstates, and (2) the first actuator element and the second actuatorelement are in a collapsed actuation state; and the recovery device isplaceable in the second, radially expanded configuration when (1) theblocking balloons are in inflated states, and (2) the first actuatorelement and the second actuator element are in an expanded actuationstate.
 8. The assembly according to claim 1, further comprising: ahollow recovery catheter having a sidewall and defining a recoverylumen.
 9. The assembly according to claim 8, further comprising: alateral passageway extending through the central portion of the recoverydevice and the sidewall of the recovery catheter, the parts of theproximal and distal blocking portions and the central portion at leastpartially defining the collection chamber being liquid impervious withthe exception of the passageway; whereby liquid in the collectionchamber can pass through the passageway and into and through therecovery lumen.
 10. The assembly according to claim 9, wherein: therecovery catheter comprises proximal, intermediate and distal portions;the lateral passageway is located along the intermediate portion of therecovery catheter; a blood pump located along the distal portion of therecovery catheter; and a filter element located along the distal portionof the recovery catheter for filtering out at least one agent from fluidflow through the recovery catheter lumen.
 11. The assembly according toclaim 8, further comprising: a first pressure sensor at the collectionchamber; a second pressure sensor positioned distal of the recoverydevice; a filter element and a pump operably coupled to the recoverycatheter to pump fluid through the recovery catheter and filter fluidpassing through the recovery catheter; and the pump operably coupled tothe first and second pressure sensors to permit control of the pressurewithin the collection chamber during use.
 12. The assembly according toclaim 8, further comprising: a filter element and a pump operablycoupled to the recovery catheter to pump fluid through the recoverycatheter and filter fluid passing through the recovery catheter; apressure sensor proximal to the pump; and the pump operably coupled tothe pressure sensor to permit control of the pressure within thecollection chamber during use.
 13. The assembly according to claim 1,wherein the recovery device defines a return channel between theproximal and distal ends when in the second, radially expandedconfiguration.
 14. The assembly according to claim 1, wherein: therecovery device comprises proximal and distal toroidal blocking balloonsat the proximal and distal ends of the recovery device; the recoverydevice is placeable in the first, radially collapsed configuration when(1) the blocking balloons are in deflated states, and (2) the one ormore actuator element are in a collapsed actuation state; and therecovery device is placeable in the second, radially expandedconfiguration when (1) the blocking balloons are in inflated states, and(2) the one or more actuator element are in an expanded actuation state.